El presente trabajo tiene por objetivo presentar una versión del Teorema del Flujo Tubular que sirva de motivación para introducir objetos geométricos como fibrado tangente, subfibrado tangente, X-foliación, entre otros. Esta presentación resulta ser el caso 1-dimensional del Teorema de Frobenius, lo que nos permitirá ver con claridad qué tipo de problema es el que resuelve dicho teorema, facilitando la comprensión del caso k-dimensional de tan importante teorema. / The objetive of this work is to present a version of the Tubular Flow Theorem that motivates the introduction of geometric objects such as: tan- gent bundle, tangent subbundle, X-foliation, etc. This presentation becomes the 1-dimensional case of the Frobenius Theorem, which will let us see what kind of problem this theorem solves, in order to improve the comprehension of the k-dimensional case of such as important theorem.

Dissertation (Ph.D.)--Auburn University, 2006. / Abstract. Includes bibliographic references (p.29).

Zugl.: Frankfurt (Main), Univ., Diss., 2006

Apresentamos o valor de Perron combinatório de árvores, definido por Andrade e Dahl [4]. Este novo parâmetro é uma cota inferior para o valor de Perron e pode ser calculado diretamente da árvore, sem a necessidade do cálculo do espectro. Exibimos resultados de Kirkland et al. [15] que mostram como a conectividade algébrica de uma árvore pode ser obtida através do valor de Perron. Mostramos que o valor de Perron combinatório é uma boa aproximação para o valor de Perron da estrela e do caminho, conforme afirmado em [4]. Além disso, apresentamos resultados de experimentos computacionais realizados para investigar a qualidade da aproximação do valor de Perron pelo valor de Perron combinatório para árvores com até 14 vértices. Também investigamos a possibilidade de utilizar o valor de Perron combinatório para o ordenamento de árvores de diâmetro 3. / We present the combinatorial Perron value of trees, defined by Andrade and Dahl [4]. This new parameter is a lower bound to the Perron value and it can be computed directly from tree, without the need of spectrum calculation. We exhibit results from Kirkland et al. [15] that show how the the algebraic connectivity of a tree can be obtained through the Perron value. We prove that the combinatorial Perron value is a good approximation to the Perron value of the star and of the path, according to [4]. Besides we present results from computational experiments executed to investigate the quality of the approximation of the Perron value by the combinatorial Perron value for trees with up to 14 vertices. We also investigate the possibility of using the combinatorial Perron value for ordering trees of diameter 3.

In quantum information processing, the information is stored in the state of quantum mechanical systems. Since the interaction with the environment is unavoidable, there is a need for quantum error correction to protect the stored information. Until now, the methods for quantum error correction were mainly based on quantum codes that rely on the arithmetic in finite fields. In contrast, this thesis aims to develop a basic framework for quantum error correcting codes over a class of rings known as the Frobenius rings. This thesis focuses on developing the theory of stabilizer codes over the Frobenius rings and provides a systematic construction of codes over these rings. A special class of Frobenius rings called finite chain rings will be the emphasis of this thesis. The theory needed for comparing the minimum distance of stabilizer codes over the finite chain rings to that over the fields is studied in detail. This thesis finally derives that the minimum distance of stabilizer codes over finite chain rings cannot exceed the minimum distance over the fields.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1973. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 143).

In this thesis, it is proposed to examine the difference equation:(z-h) ∆-hW(z) = A(z)W(z)(1) where W(z) is a vector with two components,∆-hW(h) = W(z) – W(z-h)/h(2)Here, A(z) is a 2x2 matrix, whose elements admit factorial series representations:A (z) = R + Σ∞s=0 As+1S!/z(z+h) ••• (z+sh)(3)R and As+l are square matrices of order two and independent of z. We also assume that eigen values of R do not differ by an integer. We hope to show that if (3) converges in some half plane, then (1) will have a fundamental matris solution of the form: W(z) = S(z)ZR where S(z) is a 2x2 matrix, whose elements have convergent factorial representation in some half plane.

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Matemática Pura e Aplicada, Florianópolis, 2017. / Made available in DSpace on 2017-10-24T03:21:31Z (GMT). No. of bitstreams: 1 347946.pdf: 810479 bytes, checksum: 1c2f1fb7f8c41b3cc057f71e30a878d5 (MD5) Previous issue date: 2017 / Sejam G um grupo finito que age em uma categoria de fusão C, H um subgrupo de G e M uma categoria módulo sobre C. Se M é um C-módulo H-equivariante, existe a equivariantização MH. O presente trabalho caracteriza os objetos simples em MH, em que M é uma categoria módulo indecomponível semissimples, bem como traz um estudo detalhado das ferramentas usadas para tal.<br> / Abstract : Let G be a group acting on a fusion category C, H a subgroup of G and M a module category over C. If M is a H-equivariant C-module then there exists the equivariantization MH. This work characterizes simple objects in MH, where M is a semisimple indecomposable module category, as well as presents a detailed study of the tools used for it.

In this thesis we study deformations of functions on singular varieties with a view toward Frobenius manifolds. <br /><br />Chapter 2 is mainly introductory. We prove standard results in deformation theory for which we do not know a suitable reference. We also give a construction of the miniversal deformation of a function on a singular space that to the best of our knowledge does not appear in this form in literature. <br /><br />In Chapter 3 we find a sufficient condition for the dimension of the base space of the miniversal deformation to be equal to the number of critical points into which the original singularity splits. We show that it holds for functions on smoothable and unobstructed curves and for function on isolated complete intersections singularities, unifying under the same argument previously known results. <br /><br />In Chapter 4 we use the previous results to construct a multiplicative structure known as F -manifold on the base space of the miniversal deformation. We relate our construction to the theory of Frobenius manifolds by means of an example: mirrors of weighted projective lines.<br /><br />The appendix is joint work with D. Mond. We study unfolding of composed functions under a suitable deformation category. It also yields an F-manifold structure on the base space, which we use to answer some questions raised by V. Goryunov and V. Zakalyukin on the discriminant on matrix deformations.

Zugl.: Frankfurt (Main), Univ., Diss., 2006